[DataGrid] Fix disposed object access error in EntityFrameworkAdapter [#2769]

[miguelhasse]

Pull Request

📖 Description

Fix for reported issue #2769

🎫 Issues

FIX: Semphore slim disposed object access error in EntityFrameworkAdapter and FluentDataGrid

📑 Test Plan

Use the scenario described in issue #2769 to manually test.

✅ Checklist

General

• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have added Unit Tests for my new component
• I have modified an existing component
• I have validated the Unit Tests for an existing component